How Long Does Tylenol Stay In Your System?

In our latest question and answer, our pharmacist discusses how long Tylenol stays in your system after your last dose.

Question

Hello, I am looking to go to an event this weekend where alcohol will be served. I've always read not to mix Tylenol and alcohol. I had some Tylenol the other day and just want to know how long it stays in my system.

Asked by Tonya On Aug 10, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Aug 10, 2022
Last updated Aug 10, 2022

Key points

  • Tylenol (acetaminophen) has a relatively short half-life in healthy adults, around 2 to 3 hours.
  • In healthy adults, Tylenol (acetaminophen) will stay in your system for around 10 to 15 hours. In infants and children, it will last slightly longer
  • Tylenol (acetaminophen) will also stay in your system longer if you have kidney or liver disease.

Answer

Hello and thanks for reaching out to us! This is a great question and we're more than happy to straighten this out for you!

Tylenol Has A Short Half-Life

The most important thing to know here is that Tylenol (acetaminophen) has a relatively short half-life, which is a common measure used to determine how long a drug substance stays in a person's system.

The half-life of a is essentially a measure of long it takes the body to metabolize 50% of a drug. It generally takes about 4 to 5 half-lives for a drug to be considered completely eliminated from someone's system. So, for example, if the half-life of a drug is 5 hours, it would take about 20-25 hours for the drug to be eliminated from the body. This is a little bit of a simplification as there can be other factors at play, but it's a good generalization.

What Is The Half-Life Of Tylenol?

Tylenol (acetaminophen) has a half-life of 2 to 3 hours in healthy adults.

This half-life will vary depending on the individual, however. The half-life will be longer in those with kidney impairment (around 5 hours) and in those with liver impairment (varies depending on the degree of impairment).

Additionally, the half-life of Tylenol is longer in neonates (~5-11 hours), infants (~4 hours), and children (~3 hours).

How Long In Tylenol In Your System For?

Due to the short half-life of Tylenol, in healthy adults, Tylenol (acetaminophen) will stay in your system for about 10-15 hours. So, after your last dose, it will be completely metabolized and eliminated in less than one day.

Now, again, the half-life of Tylenol varies by individual, and 10-15 hours is the measure for healthy adults. If you have kidney or liver impairment, it will last longer.

Tylenol also lasts longer in neonates, infants, and children as they don't yet have the full development of some of the metabolic pathways that process the drug. For infants, Tylenol will generally stay in the system for 16-20 hours and children will be, for the most part, on par with adults (10-15 hours).

Alcohol With Tylenol

You are right that you should avoid combining alcohol and Tylenol. Both can put stress on the liver and overuse of Tylenol is one of the most common causes of liver damage. Combining Tylenol and alcohol puts you even more at risk for liver damage

If you want Tylenol completely out of your system before having an alcoholic beverage, you will want to wait at least 10-15 hours after your last dose.

How Long Does Tylenol Last?

I want to point out that the question of 'how long does Tylenol stay in your system' is different from 'how long does Tylenol last'. Each dose of Tylenol lasts around 4 to 6 hours (i.e. has pain-relieving/fever-reducing effects). Tylenol does make an extended-release product, known as Tylenol Arthritis, which lasts 8 hours per dose.

As I've written in this article though, in regard to Tylenol being cleared from your system, that takes longer (15-20 hours in healthy adults).

Final Words

Thanks again for your question and please reach out to us again in the future if anything comes up!

References

  • Acetaminophen kinetics in the elderly, PubMed
  • Kinetics and metabolism of paracetamol and phenacetin, PubMed
  • Kinetics of acetaminophen absorption and gastric emptying in man, PubMed
  • PharmGKB summary: Pathways of acetaminophen metabolism at the therapeutic versus toxic doses, PubMed
  • Acetaminophen Toxicity: What Pharmacists Need to Know, USPharmacist

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 11 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Feel free to send him an email at Hello@HelloPharmacist.com! You can also connect with Dr. Brian Staiger on LinkedIn.

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